1. Technical Field
The following relates generally to roadway construction and repair, and more particularly, to the formation, installation and system for replacing and/or intermittent repair of a pre-fabricated pavement slab, and the slab so formed.
2. State of the Art
Many of our vital utilities such as water, sewer, storm and gas lines, telephone and other communication cables, heating and cooling lines are buried underground to keep them out of harm's way and protected from the elements. While many of these were wisely installed outside of highway pavement areas, to facilitate access for repair or replacement purposes, many more were not because there were no available alternative locations.
Under-pavement utilities are particularly common in cities where there is no other space to locate them.
Repair of under-pavement utilities inherently involves removal and replacement of the pavement above the utility. The process typically involves sawing the existing pavement along the boundaries of the trench, removal of the pavement and the earth below it, repair of the utility, backfilling the excavated material and finally, restoring the pavement to its original condition.
Acceptable restoration of pavement over utility trenches in heavily traveled areas, such as city intersections, has been an age-old problem. Not only is the backfilling process often done hastily but the pavement is frequently replaced with “flexible” asphalt pavement. When the poorly-compacted backfill settles, the pavement follows leaving “classic” bumps at such locations.
A proper restoration of concrete pavement that has been removed for utility repair requires insertion of load transfer dowels to transfer load across joints between adjacent slabs of the new concrete pavement. Properly inserting dowels in replacement pavement is a laborious and time consuming process that is sometimes omitted in heavily traveled areas, in the interest of limiting repair time, which omission may result in a concrete “patch” that may, and often does, settle as the newly installed backfill over the utility settles.
An alternative to sawing the pavement for a “specific” trench directly over the utility is to remove entire pavement slabs that have been placed in the general vicinity of the desired trench. This is done by cutting the dowels in the existing joints around the slab or slabs that are to be removed to free it up for removal. Once removed, the utility may be repaired. Prior to installing new cast-in-place pavement the current practice is to drill holes for new dowels in the edges of the surrounding existing pavement with a drill or other boring device. The current practice is to drill holes for the new dowels slightly offset from the original dowels which were cut in half in the removal process and remain in the existing pavement. This time-consuming process is necessary since it is extremely difficult to remove the half of the original, typically solid, steel, dowel. This practice also compromises the structural integrity of the edges of the existing pavement because holes for dowels now exist at 6 inch rather than at 12 inch centers.
Accordingly, there exists a need in the industry for a precast pavement slab and a method of installing the slab that solves these and other problems.